Don't let your worn-out chain ruin the rest of your drivetrain. This handy tool is quick and easy to use, and can save you some serious headaches. This "go-no go" chain gauge is designed to let you know when your chain reaches .5% and .75% wear, which is when most chain manufacturers recommend replacement.

Being able to easily measure you own chain takes the guesswork out of it. No more depending on someone else's opinion or wondering if the bike shop was telling the truth. I have 5 bikes, checked all the chains in 2-3 minutes and now know exactly how much wear is on them.